Which airspace classes require two-way radio communication and clearance for entry?

Which airspace classes require two-way radio communication and clearance for entry?

• A. Class B, C, and D require two-way radio communication and clearance; Class A IFR only.
• B. Class A requires two-way radio communication for entry.
• C. Class E requires two-way radio communication for all operations.
• D. All airspace classes require explicit clearance for all flights.

Answer: (A)

The important idea is how entry requirements differ by airspace class. In the U.S., entering the more tightly controlled airspaces around busy airports—Class B, Class C, and Class D—requires two-way radio communication with ATC and an explicit ATC clearance before entry. That two-way communication ensures ATC can provide instructions and maintain separation as traffic increases. Class A is IFR-only, meaning you cannot operate there VFR. Any entry into Class A must be under ATC clearance for IFR flight, and you’re in two-way communication with ATC as part of that clearance. So, this class also involves two-way radio communication, but the key point is that operations there are exclusively IFR and require clearance. Other options don’t fit because they either misstate which classes require explicit entry clearance and two-way communication or imply requirements that aren’t universal (for example, Class E often allows VFR entry without explicit ATC clearance, and not all airspace requires clearance for all flights). So the best-match idea is that Class B, C, and D require two-way radio communication and ATC clearance to enter, while Class A is IFR-only and also requires clearance (with communication as part of that IFR clearance).

The important idea is how entry requirements differ by airspace class. In the U.S., entering the more tightly controlled airspaces around busy airports—Class B, Class C, and Class D—requires two-way radio communication with ATC and an explicit ATC clearance before entry. That two-way communication ensures ATC can provide instructions and maintain separation as traffic increases.

Class A is IFR-only, meaning you cannot operate there VFR. Any entry into Class A must be under ATC clearance for IFR flight, and you’re in two-way communication with ATC as part of that clearance. So, this class also involves two-way radio communication, but the key point is that operations there are exclusively IFR and require clearance.

Other options don’t fit because they either misstate which classes require explicit entry clearance and two-way communication or imply requirements that aren’t universal (for example, Class E often allows VFR entry without explicit ATC clearance, and not all airspace requires clearance for all flights).

So the best-match idea is that Class B, C, and D require two-way radio communication and ATC clearance to enter, while Class A is IFR-only and also requires clearance (with communication as part of that IFR clearance).